A sample was selected based on their prominence in each geographical region in the service provider in the same region have been carefully selected to ensure that all respondents had experience of similar services.
The sample was selected based on the prominence of each of the geographic regions in the same region have been selected to ensure that all respondents had experienced a similar service.
The sample was selected based on the estimated range of each carrier in the same geographical region region is selected to ensure that all respondents experienced similar services.